Fittings have sharper barbs than standard barbed hose fittings to grip rubber push-on hose with no clamps or ferrules required. The more you pull on the fittings, the tighter the hose will grip. 304 stainless steel fittings have very good corrosion resistance.Fittings with a threaded end are also known as hose nipples.The optional installation tool (sold separately) allows you to connect large quantities of barbed fittings to push-on hose. Use the built-in cutter to squarely cut the hose without fraying. Then, clamp the hose into the tool’s vise and apply light pressure on the handle to drive into the fitting. Replace a damaged ring with a ring stop (sold separately).Note: To ensure proper connection, the barbed end has to be pushed in all the way, with the hose end concealed by the ring.